NSG is legally non-binding so their opinion doesn't make any difference in the deal.
I'm not sure that the complaints I saw about the Sino-Pakistan nuclear deal, were motivated by things like the NSG, but rather more for geopolitical reasons (i.e. both countries are rivals to India). Just my opinion.
The nations who signed the NSG promised not the break the rules...India has a unanimous waiver from the NSG, Pakistan does not.